Controlling mechanism for calculating machine

ABSTRACT

Control mechanism for a calculating machine including a keyboard on which is mounted a plurality of digit keys and a pair of control keys each one of which provides for two calculating machine functions, one control key providing for both an adding function and a sub-totaling function and the other control key providing for both a subtracting function and a totaling functioning and a locking mechanism for preventing the actuation of one control key when the other control key is actuated. Selecting means are provided for selecting which one of the two calculating machine functions will be performed in response to actuation of each control key and the selecting means operates to select one or the other machine function depending upon whether the control key is actuated before or after actuation of any of the digit keys.

United States Patent Kawamura et al.

[151 3,685,725 [4 1 Aug. 22, 1972 CONTROLLING MECHANISM FOR CALCULATING MACHINE Inventors: Toshiki Kawamura; Tohru Ohneda, both of Chiba; Yasuaki Nomura, Tokyo; Kikuo Taguchi, Chiba, all of Japan Kabushiki Kaisha Hattori, Tokeiten, Japan Filed: Dec. 30, 1968 Appl. No.: 787,762

Assignee:

US. Cl. ..235/62 F, 235/27, 235/60 TK, 235/60.48

Int. Cl. ..G06c 21/04 Field of Search....235/62, 27, 60.49, 60.50, 145, 235/60.48

References Cited UNITED STATES PATENTS 6/1960 Anderson ..235/60 12/ l 950 Werner ..235/7 9/ 1957 Christian et a]. ..235/60.48 11/1958 Anderson ..235/62 3,042,300 7/1962 Anderson ..235/62 3,279,694 10/1966 Barnes, Jr. et al. .....235/60.48 3,464,623 9/1969 Busch ..235/ 130 Primary Examiner-Stephen J. Tomsky Attorney-Robert E. Burns ABSTRACT Control mechanism for a calculating machine includ ing a keyboard on which is mounted a plurality of digit keys and a pair of control keys each one of which'provides for two calculating machine functions, one control key providing for both an adding function and a sub-totaling function and the other control key providing for both a subtracting function and a totaling functioning and a locking mechanism for preventing the actuation of one control key when the other control key is actuated. Selecting means are provided for selecting which one of the two calculating machine functions will be performedin response to actuation of each control key and the selecting means operates to select one or the other machine function depending upon whether the control key is actuated before or after actuation of any of the digit keys.

7 Claims, 6 Drawing Figures PATENTEBwszz 1972 I 3,685 725 sum 1 or 3 ELL PAIENTED M1822 I972 CONTROLLING MECHANISM FOR CALCULATING MACHINE The present invention relates to calculating machines which utilize keyboards having mounted thereon a plurality of keys which when properly operated function to carry out such operations as addition, subtraction, totaling and sub-totaling etcetera, and the recordation of the results on suitable paper mounted in the machine.

In the prior art, it is common to have a separate key for each of the addition, subtraction, sub-totaling and totaling functions. It has been found that a reduction in the number of keys for the last named functions results in more efficient operation of the mechanism because, particularly, the operator is less likely to depress the wrong key. The present invention provides apparatus which serves to reduce the number of keys that are utilized for the addition, subtraction, sub-total and total functions to two keys which when operated properly provide all of the last named functions. Selecting means are provided for selecting which one of the two calculating machine functions will'be carried out in response to depression of each control key depending upon whether the particular control key is depressed prior or subsequent to depression of any of the digit keys. In addition, the present invention provides locking apparatus that prevents the actuation of one of the control keys when the other is already actuated, thereby preventing erroneous results should both keys be actuated simultaneously.

It is, therefore, an object of the present invention to provide an improved calculating machine.

It is another object of the present invention to pro-- vide apparatus for a calculating machine which serves to reduce the number of keys required to perform a predetermined number of calculating machine functions.

It is still another object of the present invention to provide an improved key locking mechanism for a calculating machine.

It is a further object of the present invention to provide a more economically manufactured calculating machine.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a calculating machine which embodies the present invention;

FIG. 2 is an enlarged perspective view, partially broken away, of a portion of the apparatus constituting the present invention;

FIG. 3 is an enlarged elevational view, partiallyin section and broken away, of a portion of the apparatus constituting the present invention;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 3;

FIG. 5 is an enlarged elevational view, partially in section and broken away, of another embodiment of the key locking mechanism of the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1 there is shown a perspective view of a calculating machine having a keyboard 1 on the upper face thereof and a plurality of manually operable keys on the keyboard 1', including a clear key 2 a plurality of digit keys 3, a non-add key 6 and two control keys 7 and 8. The control key 7 has two functions, one an adding function and the other a sub-totaling function and the control key 8 also has two functions, one a subtracting function and the other a totaling function, all of which will be explained below. Each'one-of the keys described may be operated simply by depressing the particular key.

Turning now to FIGS. 2, 3 and 4 which show the control mechanism in detail, a plurality of function instruction transmittal elements or-control levers (FIG. 2) are disclosed including an elongated adding control'lever 10, an elongated sub-total control lever 11 extending parallel to but spaced from the control lever 10, an elongated total control lever 12 extending parallel with but spaced from the lever 11, an elongated subtracting control lever 13 extending parallel with but spaced from the lever 12 and an elongated non-add control lever 14 extending parallel with but spaced from the lever 13. Each of the control levers 10 through 14 is provided with two guide slots 77 and a pair of guide rods 78 extend respectively through the guide slots in each control lever. Each of the levers 10 through 14 is formed with a depending spring arm integrally formed with its respective control lever intermediate the ends thereof and extends through a respective opening 79 in a supporting base plate 15. Connected by one end to each one of the spring arm 80 is a coil spring 17 which is connected to a respective one of a number of spaced studs 16 secured to the underside of the base plate 15, springs 17 tending to bias the respective control levers endwise in the direction indicated by the arrow A shown in FIG. 2. Each of the elongated control levers 10 through 13 is formed with a pair of substantially rectangular tabs spaced from each other by a substantially rectangular slot. Thus, as can be seen by reference to FIG. 2, the control levers 10, 11, 12 and 13 include the tabs 18a and 19a, 18b and 19b 18c and, and 18d and 19d, respectively, spaced by the slots 10a, 10b, 10c, and 10d, respectively. The end section of the non-add lever 14 corresponding to the ends of the other control levers just described is formed with a locking tab 18c.

The control key 7, also referred to as the add and sub-total key 7, is secured to the upper ends of an irregularly stepped substantially vertical lever arm 20 which projects through the keyboard I, the lever arm 20 including a vertical section having formed therein a secured at its other end to a stud 51 secured to and extending at right angles from the inner surface of the side plate 22b, the stud 51 being spaced upwardly relatively to the point at which the spring 24 is secured to the lever arm 20, thereby to bias the lever 20 upwardly (FIG. 2). A substantially U-shaped stop lever 25 is pivotally mounted by its parallel legs on a shaft 31 that is supported by the plates 22a and 22b between which the shaft extends. The stop lever 25 includes a face 25a which may be pivoted into engagement with the locking tabs 18a and 18b and a leg 25b. The stop lever 25 may be pivoted into or out of engagement with the tabs 18a and 18b by the vertical motion of the lever arm 20 to which the leg 25b is connected, the vertical motion of the lever arm 20 being limited by the length of the slot 21 which slidably receives the guide rod 23. Thus it can be seen that the control key 7 and its associated mechanisms function in either of two modes, i.e., add mode and a sub-total mode, to selectively transmit the desired machine function to other well known mechanisms whereby the appropriate function is carried out.

The control key 8, also referred to as the subtract and total key 8, is secured to the upper ends of a vertically disposed flat lever arm 26 which includes a vertical elongated slot 27, which in turn receives a horizontally disposed horizontal rod 28 supported by and extending between the side plates 22a and 22b between which the guide rod 28 extends. To a lower (FIG. 2) section of the lever 26 there is connected by one of its ends a coil spring 29, that is connected by its other end to the guide rod 52 which is mounted vertically relatively to the lever arm 26, thereby tending to bias the lever arm 26 upwardly. The lower end section of the lever arm 26 is connected to the free end section of a leg 30b of a substantially U-shaped stop lever 30 which includes a face 30a, the stop lever 30 being pivotally mounted by its parallel legs to the shaft 31. The vertical motion of the lever arm 26 serves to pivot the face 30a into or out of engagement with the locking tabs 18c and 18d. Like the control key 7, the control key 8 and its associated mechanisms operate in either of two modes, a subtract mode and a total mode, to selectively transmit the desired machine function to other well known mechanism within the calculating machine whereby the appropriate machine function is performed.

The non-add key 6 is secured to the upper (FIG. 2) end of a flat vertically disposed flat lever arm 32, irregularly stepped, whose upper end section projects through an opening in the keyboard 1 and whose lower end section is formed with a vertical elongated slot 33 that receives a horizontally disposed guide bar 34 supported by and between the side plates 22a and 22b between which the guide bar 34 extends. A coil spring 35 is connected by one end to the lower section of the lever arm 32 and by its other end to the horizontal rod 52 which is spaced vertically relatively to the lower section of the lever 32, thereby tending to bias the lever 32 upwardly (FIG. 2). Connected to the lower end section of the lever arm 32 are the elongated arms 39 which connect the lever 32 to the end of the leg 36b of the substantially U-shaped stop lever 36. The stop lever 36 includes a face 36a, that is brought into or out of engagement with the locking tab l8e, when the non-add key is actuated thereby to pivot the stop lever 36 about the shaft 31 on which it is rotatably mounted by its parallel legs.

In FIGS. 3 and 4, there is shown a select lever 41 which is utilized to free one or the other of the two control levers actuated when one or the other of the control keys 7 or 8 is depressed. The select lever 41 includes a vertically (FIG. 3) disposed elongated flat plate 41a, that extends parallel with but spaced from the faces 25a, 30a, and 36a. The free end section of the plate 410 projects through an elongated vertical slot 45 formed in the side plate 22a and includes at its end a depending tail 46 which extends beneath the bottom of the slot 45. The plate 41a is also formed with the depending locking lugs 47a, 47b and 470 spaced by the slots 48a and 48b and including the slots 480 between v the lug 47c and the tail 46. The plate 410 is aligned with the slots 10a through 10d formed in the control levers 10, 11, 12 and 13, respectively. The select lever 41 also includes a second vertical flat plate 41b that is integrally formed with the plate 41a extends at right angles thereto but parallel with the side plates 22a and 22b. The flat plate 41b is formed with a circular aperture 42 that receives a shaft 44 supported by and between the side plates 22a and 22b. The shaft 44 has mounted thereon a pin carriage 43 which includes a plurality of selector pins 49 each one of which-is actuated when a corresponding one of the digit keys 3 is depressed. A coil spring 50 is mounted about the shaft 44 between the plate 41b and the side plate 22a, thereby to bias the select lever 41 to the left as seen in FIG. 3. -As is conventional in the calculating machine art, each time that one of the digit keys 3 is depressed, the pin carriage 43 is moved to the left (FIG. 3) by a mechanism not shown. Since the plate 41b is biased up against the carriage 43 by the spring 50 as soon as one of the digit keys 3 is depressed, the select lever 41 will move to the left bringing the tall 46 into engagement with the side plate 220, thereby preventing further leftward movement of the lever 41. It is noted that each of they slots 48a and 48b have a length equal to the distance between the side plate 22a and the inner side of the tail 46 as seen in FIG. 3, the lengths being equal to the distance that the carriage 43 is moved leftward upon the actuation of one of the digit keys 3.

The operation of the aforesaid mechanism will now be described. In the neutral position when the controlling mechanism is not operated, the control levers 10 through 14 are in their extended positions in the direction B as indicated in FIG. 2 with the locking tabs 18a through 18d brought up flush against the faces 25a and 30a, and the locking tab l8e brought up flush against the face 36a. In addition, the select lever 41 is in its extended position which as shown in FIG. 3 extends to the right as far as it can go. In the neutral or extended position, the lug 47a is received by the adding control lever slot 10a, the slot 48a receives the subtotal control lever 11, the slot 48b receives the total control lever 12, the subtracting lever slot 10d receives the lug 47c, and the slot formed between the lug 47c and the tail 46 receives the non-add control lever 14. With the elements positioned as described above, and the operator wishes to record a plurality of numbers for addition by depressing the digit keys 3, he need merely depress the desired digit keys and then the add and subtotal control key 7. In explanation of the last, when the operator depresses the first of the digit keys 3 the carriage 43 is moved to the left (FIG. 3) and the spring 50 urges the select lever 41 to the left to bring the tail 46 into engagement with the outside surface of the side plate 22a, thereby moving the lugs 47a, 47b and 47c leftward a distance corresponding to the length of the slots 48a and 48b. With the select lever 41 now in its retracted position the slot 48a receives the adding control lever 10, the lug 47b is received by the slot b in the sub-total lever 11, the lug 470 is received by the slot 10c in the total control lever 12 and the subtract control lever 13 is received by the slot 480. Thus, when the add and the sub-total control key 7 is depressed and the stop lever 25 is pivoted upwardly, thereby freeing the levers 10 and 11 from engagementwith the face 250, the spring 17 tends to move the levers 10 and 11 in the direction indicated by the arrow A. However, because of the fact that the lug 47b is now received by the slot 10b, the sub-total lever 11 is not free to move in the direction indicated by the arrow A but since the add lever 10 is'received by the slots 48a the add lever 10 is now free to move in the direction of the arrow A. By conventional means (not shown) the movement of the add lever 10 in the direction of the arrow A serves to transmit the information presented by the depression of the digit keys 3 to a plurality of cams which perform th adding function.

When it is desired to use the sub-total function of the control key 7 it is merely necessary to depress the control key 7 without depressing one of the digit keys 3, i.e., with the select lever 41 in the position shown in FIG. 3, wherein the lug 47a is received by the slot 10a in the add lever 10 and the sub-total lever 11 is received by the slot 48a. With the select lever 41 in the position as shown in FIG. 3, therefore, it can be understood that by depressing the control key 7 to pivot the stop lever 25 upwardly to bring the face 25a out of engagement with the locking tabs 18a and 18b the subtotal lever 11 is free to move in the direction of the arrow A due to the urging of the spring 17 while the add lever 10 is prevented from moving in the direction of the arrow A by the lug 47a. As in the case of the add function of the control key 7, when the sub-total lever 11 moves in the direction of the arrow A, it transmits information to a conventional mechanism (not shown) which instructs such mechanism to perform the subtotal function. It is noted that after each of the add and sub-total operations the select lever 41 is returned to the position shown in FIG. 3, thereby to ready the machine for the next operation.

Turning now to the subtract and total functions performed by the control key 8, it should be understood that the mechanism involved operates in the same way as the mechanism associated with the control key 7. Thus, after a series of digit keys 3 have been depressed and the control key 8 is subsequently depressed the subtract function of the control key 8 will be carried out, and if the control key 8 is depressed again the totaling function of the control key 8 will be carried out. When it is desired to subtract and the digit keys 3 are depressed, the select lever 41 moves to the left (FIG. 3) and the subtracting control lever 13 is moved into the slot 48b, while the slot 10c of the totaling lever 12 receives the lug 47b. When the control lever 8 is subsequently depressed pivoting the stop lever 30 upwardly and the face 30a away from the locking tabs 18c and 18d, the subtracting lever 13 is free to be pulled endwise in the direction of the arrow A (FIG. 2) are the corresponding spring 17, however, the totaling lever 12 is prevented from being moved in the same direction by the lug 47b which engages the slot 10c. The motion of the subtracting lever 13 in the direction of the arrow A transmits an instruction to conventional cam mechanism (not shown) which willcarry out the desired subtracting function. Thereafter, if the control lever 8 is depressed, i.e., following the first depression of the control key 8, the totaling function will be carried out. Thus, since the select lever 41 has been returned to its original position as shown in FIG. 3, the slot 10d in the subtracting lever 13 receives the lug 47c while the slot 48b receives the totaling lever 12. When the control key 8 is depressed and the stop lever 30 is pivoted upwardly (FIG. 2) the totaling lever 12 is free to be urged in the A direction by-its corresponding spring 17 while the subtracting lever 13 is held against such motion by the lug 47c..Again, a mechanism not shown in thedrawings is activated by the rearward motion of the totaling lever 12 which will carry out the totaling function desired.

The mechanism for preventing the simultaneous depression of two or more of the keys 6, 7 and 8 will now be described in detail. Referring in particular to FIGS. 2 and 4, an elongated substantially rectangular locking plate 53 is mounted between the lever arms 26 and 32 so that the front faces of the locking plate 53 are parallel with the flat faces of the lever arms 26 and 32. The lower edge of the plate 53rests on the guide rods 23 and 28 and the guide bar 34 while the upper edge of the plate 53 is in contact with the horizontal rod 52 thereby capturing the plate 53 between them as seen in FIG. 4. The locking plate 33 is formed with four slots, three of which, 57, 58 and 59 are connected and form an inverted substantially U-shaped slot in one half of the locking plate 53 as shown in FIG. 4, while the fourth slot, 60, is elongated and has an end that opens out of the top of the other end section of the plate 53. The locking pins 54 and 55 by reason of their insertion in the plate 53 provide further support for the plate, along with the rods 23 and 28 and the bar 34. The slot 59 is substantially horizontal and is positioned between the angled slots 57 and 58 which diverge from opposite ends of the slot 59, the slots 57, 58 and 59 being adapted slidingly to receive the locking pins 54 and 55, while the slot 60 is adapted slidingly to receive the locking pin 56. The locking pins 54, 55 and 56 are secured to and extend at right angles from vertical faces of the lever arms 20, 26 and 32, respectively. In the extended or neutral position of the control pins 7 and 8, the locking pins 54 and 55 are positioned as shown in FIG. 4 at the top of the slots 57 and 58,

' respectively, at the junction between those slots and the plate 53 is moved endwise in the direction of the arrow A shown in FIG. 4. When the plate 53 is moved in the direction of the arrow A, the pins 55 and 56 are no longer positioned in alignment with the corresponding slots 58 and 60, thus, depression of the keys 8 or 6 is resisted by the engagement of the locking pins 55 or 56 with the corresponding surfaces of the slot 59 and the upper edge of the plate 53. When the control key 7 is released and brought back to its original position by the spring 24, the pin 54 moves upwardly and into engagement with the opposite surface of the slot 57 and along that surface thereby to move the plate 53 endwise back to its original position as shown in FIG. 4. The locking plate 53 cooperates with the locking pin 55 when the control key 8 is depressed in the same manner as when the control key 7 is depressed, thereby preventing the depression of the other two keys 7 or 6. When the nonadd key 6 is depressed, with the control keys 7 and 8 in their retracted or neutral positions, the locking pin 56 is brought down into the slot 60 of the locking plate 53.

With the locking pin 56 in the vertical slot 60, the plate 53 may not be moved endwise. Thus, if either of the control keys 7 or 8 are depressed, the respective locking pins 54 or 55 are brought into contact with the respective slots 57 or 58 but are prevented from moving downwardly along the surfaces of said slots because the plate 53 cannot move endwise. When the non-add key 6 is released by the operator a spring 35 connected by one of its ends to the lower end of the lever arm 32 and by its other end to the horizontal rod 52 spaced vertically relatively to the bottom of the lever arm 32 urges the lever arm 32 upwardly and therefore the nonadd key 6 back to its original position.

FIG. shows another embodiment of the locking mechanism described immediately above. All of the parts remain the same except as noted. Thus, the elongated substantially rectangular locking plate 61 shown in FIG. 5 provides the same end results as that of the locking plate 53 described above. The locking plate 61 extends parallel with the side plates 22a and 22b and is mounted between the lever arms 20 and 26. as in the previous embodiment and is mounted between the guide rods 23 and 28 and the guide bar 34 all of which are disposed beneath the lower edge of the plate 61, and the horizontal rod 52. Contrary to the prior described embodiment wherein all of the rods 52, 23 and 28 and the bar 34 are in contact with the edges of the locking plate 53, there is a sufficient spacing between the rod 52 on the one hand and on the other hand the rods 23, 28 and the bar 34 so that the locking plate 61 may move vertically (FIG. 5) a small distance therebetween. The locking plate 61 is secured to the upper end section of a pair of spaced leaf springs 62 to the bottom end sections of which are connected to the supporting base plate 15. Since the leaf springs 62 are resilient, it can be understood that the locking plate 61 can be moved in either of the directions indicated by the arrows A and B in FIG. 5. The locking plate 61 is formed near one end section with a substantially V- shaped slot having surfaces 63 and 64 which converge on a substantially U-shaped slot 65 formed in the locking plate 61 in the general area at which the surfaces 63 and 64 would normally meet. In addition, near the other end section of the locking plate 61, there is formed a vertical slot 66 which opens out of the top edge of the plate 61 and is adapted to receive the locking pin 56 in sliding engagement therewith. The upper part of the surface 63, which functions as a camming surface, is positioned as seen in FIG. 5 directly beneath the locking pin 54 and the upper part of the surface 64, which also functionsas a carning surface is positioned directly beneath the locking pin 55. When, for example, the control key 7 is depressed the locking pin 54 moves down into engagement with the surface 63 and thereafter slides along the surface 63 until it reaches the U-shaped slot 65 which is formed to receive the locking pin 54 in a snug fit. As the locking pin 54 slides along the surface 63, the locking plate 61 is moved in the direction indicated by the B arrow, thereby moving the surface 64 out from beneath the locking pin 55 and the slot 66 out from beneath the locking pin 56'. Thus, it can be understood that in such a position when either of the control keys 6.or 8 are depressed, they are resisted by the upper edges of the locking plate 6 1 and cannot bepressed down into their actuated position. When the control key 8 is depressed, the locking plate 61 is moved in the direction indicated by the A arrow and the surface 63 is moved out from beneath the locking pin 54 and the slot 66 is moved out from beneath the locking pin 56, thereby preventing the actuation of either of the keys 8 or 6 should pres sure be applied to them. In either of the last two examples, when control keys 7 or 8 is released after having been moved down into their actuating position, the corresponding springs 24 or 29 return the control keys to their original position and since the springs 62 are resilient they return the locking plate 61' back to its original position as shown in FIG. 5. The slot 66 and pin 56 arrangement functions similarly as the slot and pin 56 arrangement disclosed in the prior embodiment, to prevent the actuation of the control keys 7 or 8 when the non-add key 6 is depressed.

FIG. 6 discloses still another embodiment of the locking mechanism of the present invention, the elements shown in FIG. 6 being the same as those shown in FIGS. 1 through 4, except where noted. Thus, an elongated substantially rectangular locking plate 67 is mounted between the lever arm 20 on the one hand and the lever arms 26 and 32 on the other hand as in the prior embodiments. The locking plate 67 is mounted between and in contact with the guide rods 23 and 28 and the guide bar 34 on the one hand and the rod 52 on the other hand. The locking plate 67 has formed in one end section two vertical slots 73 and opening out of the upper (FIG. 6) edge of the plate 67, the slot 73 being formed on one side with a surface 72 that. angles upwardly but also in the direction of the arrow A. The vertical slot 75 includes a surface 74 that angles upwardly from approximately the mid-point of the vertical slot 75 but also in the direction of the arrow with the slot 76 when the non-add control key 6 is depressed. In addition, an inverted substantially V- shaped indent 68 is formed in the bottom edge of the locking plate 67 at approximately the midpoint thereof, as seen in FIG. 6. A substantially vertical support post 69 is secured by its lower end to the supporting base plate and has secured to its top end one end section of a leaf spring 70, the other or free end section of the leaf spring 70 having mounted thereon an upwardly extending roller 71, that is urged into contact with the surface of the indent 68. In operation when, for example, the control key 7 is depressed the locking pin 54 is urged downwardly and into engagement with the angled surface 72. As the locking pin 54 slides down the angled surface 72, the locking plate 67 is moved in the direction indicated by the arrow A in FIG. 6, thereby moving the surface 74 out from beneath the locking pin 55 and the slot 76 out from beneath the locking pin 56. In that position when the control key 8 or the non-add key 6 is attempted to be depressed, the pins 55 or 56, respectively, are brought into engagement with the top edge of the locking plate 67 which resists any further downward movement of such pins thereby preventing the actuation of the. keys 8 or 6 while the key 7 is depressed. Similarly, when the control key 8 is depressed the pin 55 is brought into sliding engagement with the surface 74 to move the locking plate 67 in the direction of the arrow B shown in FIG. 6, thereby moving the surface 72 out from beneath the pin 54 and the slot 76 out from beneath the pin 56 to prevent the actuation of the control key 7 or the non-add key 6. In both of the last mentioned instances when the keys 7 or 8 are depressed, the roller 71 is moved along the corresponding angled surface of the inverted substantially V-shaped indent 68. Since the member 70 is a leaf spring, the spring 70 will bend downwardly to permit the endwise movement of the locking plate 67, however, the tension produced by the bending of the spring 70 serves to move the locking plate 67 back to its original position when either of the control keys 7 or 8 are released. The slot 76 and pin 56 arrangement shown in FIG. 6 functions similarly as the slot 60 and pin 56 arrangement in FIG. 4 to prevent the actuation of the control keys 7 or 8 when the non-add key 6 is depressed.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of our invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

What we claim and desired to secure by Letters Patent is:

1. A control mechanism for a calculating machine comprising: a manually actuatable control member; function instruction transmittal means for transmitting instructions of one of two different calculating machine functions in response to actuation of said control releasably and selectively engaging s id two movable control levers to prevent movemen 0 same and means for operating said releasable means; and selection means for selecting which one of the two calculating machine functions will be transmitted by said function instruction transmittal means upon actuation of said control member, said selection means including a movable select lever having a lug thereon selectively engageable with the slots in said two movable control levers, and means for moving said lug out of engagement with the slot in one of said two control levers to free same for movement and for moving said lug into engagement with the slot in the other of said two control levers to lock same against movement.

2. Control mechanism as set forth in claim I including a second manually actuable control member and means for preventing the actuation of I one of said manually actuable control members while the other of said manually actuable members is actuated.

3. Control apparatus as set forth in claim 2 wherein said means for preventing the actuation of one of said manually actuable control member includes an endwise movable plate including therein means defining a plurality of slots, and wherein each of said manually actuable control members includes a pin, selectively engagable with a respective one of said slots in response to actuation of its respective control member to move said plate endwise.

4. Control apparatus as set forth in claim ll including a plurality of manually actuable control members and preventing means for preventing the actuation of any of the other of said manually actuable control members while one of said manually actuable control members is actuated.

5. Control apparatus as set forth in claim 4 wherein said preventing means includes an endwise movable plate, said plate including a plurality of pin engaging surfaces, each of said plurality of manually actuable control members including a pin engagable with a respective one of said plurality of pin engagable surfaces, said surfaces being arranged so that the actuation of one of said members moves the respective pin therefor along the surface to move said plate endwise whereby the other of the surfaces are moved relative to their respective pins.

6. Control apparatus as set forth in claim 5 including a pair of spaced flexible support arms, each of said flexible arms being connected by one end section to said plate and by the other end section to a fixed support.

7. Control apparatus as set forth in claim 5 wherein said plate includes a substantially V-shaped groove and including a resilient member and a roller connected to said resilient member and engagable with said V- shaped groove. 

1. A control mechanism for a calculating machine comprising: a manually actuatable control member; function instruction transmittal means for transmitting instructions of one of two different calculating machine functions in response to actuation of said control member, said function instruction transmittal means including two movable control levers each having means therein defining a slot, and means for moving said two control levers comprising releasable means for releasably and selectively engaging said two movable control levers to prevent movement of same and means for operating said releasable means; and selection means for selecting which one of the two calculating machine functions will be transmitted by said function instruction transmittal means upon actuation of said control member, said selection means including a movable select lever having a lug thereon selectively engageable with the slots in said two movable control levers, and means for moving said lug out of engagement with the slot in one of said two control levers to free same for movement and for moving said lug into engagement with the slot in the other of said two control levers to lock same against movement.
 2. Control mechanism as set forth in claim 1 including a second manually actuable control member and means for preventing the actuation of one of said manually actuable control members while the other of said manually actuable members is actuated.
 3. Control apparatus as set forth in claim 2 wherein said means for preventing the actuation of one of said manually actuable control member includes an endwise movable plate including therein means defining a plurality of slots, and wherein each of said manually actuable control members includes a pin, selectively engagable with a respective one of said slots in response to actuation of its respective control member to move said plate endwise.
 4. Control apparatus as set forth in claim 1 including a plurality of manually actuable control members and preventing means for preventing the actuation of any of the other of said manually actuable control members while one of said manually actuable control members is actuated.
 5. Control apparatus as set forth in claim 4 wherein said preventing means includes an endwise movable plate, said plate including a plurality of pin engaging surfaces, each of said plurality of manually actuable control members including a pin engagable with a respective one of said plurality of pin engagable surfaces, said surfaces being arranged so that the actuation of one of said members moves the respective pin therefor along the surface to move said plate endwise whereby the other of the surfaces are moved relative to their respective pins.
 6. Control apparatus as set forth in claim 5 including a pair of spaced flexible support arms, each of said flexible arms being connected by one end section to said plate and by the other end section to a fixed support.
 7. Control apparatus as set forth in claim 5 wherein said plate includes a substantially V-shaped groove and including a resilient member and a roller connected to said resilient member and engagable with said V-shaped groove. 